1. Field of the Invention
This invention relates to an ink-jet recording apparatus in which an ink drop is discharged from a nozzle opening to print a pattern on a recording medium.
2. Background
Since an ink-jet recording apparatus uses a recording head in which ink in a pressure generating chamber is pressurized by a piezoelectric vibrator or a heating element to thereby discharge an ink drop from a nozzle opening, countermeasures are required to prevent the lowering of printing quality caused by ink drying and dust deposition in the vicinity of the nozzle opening.
As one of the countermeasures, a flushing operation is carried out in a manner such that a recording head is moved to an ink receiving member such as a capping means, or the like, provided in a standby position of a non-printing region to discharge an ink drop from the nozzle opening regardless of printing data whenever a predetermined time, for example, of 20 seconds is passed in a state where the recording head is opened from the capping means for printing or standby.
According to such flushing operation, although nozzle opening choking generated in the recording head opened from the capping means in a running state can be eliminated by such flushing, choking generated in the case where the recording head is left for a long time in a power-off state or left for a long time without capping because of an accident, or the like, cannot be eliminated.
In such a case, the recording head is sealed by a capping means and negative pressure is applied to the capping means from a suction pump so that a first cleaning mode is executed for forcedly sucking ink by a predetermined quantity, for example, about 0.6 cc from the nozzle opening, and, if necessary, a second cleaning mode for sucking a larger quantity of ink than the quantity of ink sucked in the first cleaning mode and a third cleaning mode for sucking a slightly larger quantity of ink than the quantity of ink sucked in the second cleaning mode and rubbing the nozzle plate by means of an elastic plate of rubber, or the like, after the completion of ink suction are executed in order in accordance with the number of times of cleaning instruction.
In this manner, choking can be eliminated in most cases, but there arises a problem that ink is used wastefully because the first cleaning mode is always applied to choking even in the case where the choking is severe so that it cannot be eliminated by suction of about 0.6 cc of ink.
Upon such circumstances, an object of the present invention is to provide an ink-jet recording apparatus having a cleaning means by which choking is eliminated securely while the quantity of consumed ink is suppressed.